48 IDA Webers!


Finally, the Webers on the Daytona Cobra Coupe are standin' tall!


Here's the short story:

The whole time, I've been fighting a heavy (sunk) float in one unit making two cylinders extremely rich. The errant float was loaded with fuel, making it heavy and subsequently the float level very, very high.

After changing the float, all fuel levels were normal, meaning the dry float settings were spot-on as verified by the wet float checks.

Further tweaks to the idle jets and jet holders revealed that the Webers are "up" and standin' tall...no transition issues at all...NONE!

This thing makes some locomotive-like STEAM, and at the same time it's completely tractable from idle to Holy Crap!

So now, driving is a pleasure and an entirely different experience!

Looking into the 'belly of the beast'...



Now, for the long story:

When the Daytona arrived from Long Island, NY, the Webers were allegedly 'gone through' with new Weber carb kits and a 'Weber Guy'. I also received the old parts, like the floats, idle needles, and sundry other replaceable carb-kit parts.

The first thing I did was remove and completely disassemble each of the four Webers, just to check for cleanliness, passages, needles, etc. Everything looked fine. Next, I began to check and reset the float levels, dry, which is a contorted kinda process that's done in steps. What I found was the float settings were all high, by about 2~3mm, which is a lot. In addition, float level is critical in a Weber because all the circuits are affected.




Next, I proceeded to go through the linkage, which had a few problems as well: mostly mis-adjusted, quite a bit of stiction in some links and looseness in others. I also found loose nuts on two of the throttle shafts.






Another problem I found was that the accelerator cable was not driving the throttle plates to wide-open throttle (WOT)! A simple throttle cable adjustment fixed that.


And not directly related to the Weber challenges, the throttle pedal inside the Daytona was not fully attached to the pedal arm. The pedal arm has a serrated post on which the pedal assembly slips. Once fully seated on the serrations, there's a small hex that locks the pedal in place. Well, that was evidently never tightened because the pedal fell off (fortunately in the garage!). Some minor contortions accompanied by some substantial cursing and the pedal was reinstalled, this time correctly....but I digress.

Fuel pressure regulator, supplied by the electric fuel pump, was re-set to 2.5psi.


So now for the tuning part (remembering that I still have a heavy float in one carb). Following the suggestions of the "CarbFather", Jim Inglese (a huge authority on Webers!), and a number of Weber tuning parts, we started with what Jim felt was a good starting point:

WEBER PART - NEW V-1

CHOKE - 37

AUX VENTURI - 4.5

IDLE JET - 70

IDLE JET HOLDER - 80

MAIN JET - 170

AIR CORRECTOR - 155

EMULSION TUBE - F11

PUMP EXHAUST VALVE - 40

PUMP JET/NOZZLE - 50

NEEDLE ASSEMBLY - 200

COMMENT - Too Wet!

Once we found the heavy float (44 grams, compared to a good float at 22 grams!), we expected a big driveability improvement. I just knew it was rich, but didn't know for certain why. And there's a lesson here: Leave no stone unturned! Of course I very carefully measured each of the float level settings when I initially set up each carb's float system. But for some reason it didn't dawn on me to weigh each float when I had them apart so I would know that what I was working with was good-to-go

So, having replaced the (very) heavy float, and with some help and a few jetting parts from a friend who knows Webers very well, John Hirasaki, this is where we are now...and the Daytona runs fantastic:

WEBER PART - New V-10

CHOKE - 37

AUX VENTURI - 4.5

IDLE JET - 65

IDLE JET HOLDER - 100

MAIN JET - 160

AIR CORRECTOR - 155

EMULSION TUBE - F11

PUMP EXHAUST VALVE - 40

PUMP JET/NOZZLE - 50

NEEDLE ASSEMBLY - 200

COMMENT - Dialed-In & Great!

All in all, it's been a terrific Weber learning experience! I'm amazed at the simplicity of the Webers and their extreme flexibility/adjustability.

And when they're "UP", boy are they really "UP"!


ShelbyGuy


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